"I am the happiest father in the world," said Lopez, 39. "We cannot wait to welcome Baby Lopez No. 2 into our lives."

The couple's 2-year-old daughter, Gia, also appeared on the program, holding a sign that read, "I'm going to be a big sister."

Lopez and Mazza, who wed in December, met in 2008 while co-starring in the Broadway revival of A Chorus Line. This is the first marriage for Mazza and the second for Lopez, whose 2004 marriage to Ali Landry was annulled weeks later.